Yeast and process of preparing and utilizing the same.



the following is a specification.

PATENT. OFFICE.

MAXVWALLERSTEIN, 'OFJUNEW'YORK, N: Y.

YEAST AND PROCESS OF PREPARING AND UTILIZING THE SAME.

To all whom it may concern! Be it known that 1, MAX WALLERSTEIN, acitizen of the United States, residing at New York, in the county of NewYork and State of New York, have invented certain new andusefullmprovements in Yeast and Processes of Preparing and Utilizing theSame, of which This invention relates to the preparation of a yeast forfermenting wort, and to the fermentation of a wort with a yeast soprepared, the object of the invention being to provide a yeast whichpossesses particular advantages for such fermentation.

While my prepared yeast has been particularly applied to thefermentation of brewers wort, and possesses especial advantages ashereinafter explained forthe production of beer, it is applicable to thefermentation of any raw material for the production of alcohol, and theterm wort" as herein employed is intended to cover any raw materialsuitable for the production of alcohol by fermentation.

I have discovered that the addition to wort of certain salts exerts apeculiar and favorable influence upon the fermentation and upon thecharacter of the yeast; and I have further discovered that thisfavorable influence is still more pronounced when the yeast iscultivated in successive worts containing such salts in progressivelyincreasing proportions. Experiments have shown that the influence ofcalcium salts, more especially the sulfate and chlorid, is particularlybeneficial; that favorable results are also obtained with salts ofmagnesium or potassium; and that the best results are secured by the-useof worts containing salts of all of these metals, the yeast beingpropagated through several generations in each of several successiveworts containing regularly increasing proportions of such salts. I

I prefer to proceed substantially as follows: A sterilized malt wort ofa gravity of about 13 Bailing is provided containing per liter; 0.2 gr.calcium sulfate, 0.05 gr. calcium chlorid, 0.01 gr. magnesium sulfate,0.01 gr. magnesium chlorid, 0.02 gr: potassium chlorid. These salts maybe added either during or after the mashing, or to the mashing water.The wort is inoculated with a pure culture of a beer yeast and permittedto ferment. After completion of the fermentation a portion of theresultant yeast is used to inoculate a further quantity of wort of thesame composition, this sium sulfate,0.02 gr. magnesium chlorid, 0.4 'gr.potas sium chlorid. The yeast is reproduced three or four times in thiswort and then in a wort containing an in creased quantity of salt perliter, viz; 0.6 gr. calcium Specification of Letters Patent.

Application filed April 21, 1906. Serial N0. 313,005-

Patented July 2, 1907.

i sulfate, 0.15 gr. calcium chlorid, 0.03 gr. magnesium sulfate, 003 gr.magnesium chlorid, 006 gr. potassium chlorid. Several successivegenerations are cultivated in this wort, and then in worts of regularlyincreasing saline content until the concentration of the salts per literhas been increased to the following proportions;

2.0 gr. calcium sulfate, 0.5 gr. calcium chlorid, 0.1 gr. magnesiumsulfate, 0.1 gr. magnesium chlorid, 0.2 gr. potassium chlorid. Duringall of'these fermentations the temperature is carefully regulated, thefermentation starting at about 6? (3., being permitted to rise duringfermentation to 9 (3., and closing at about 2 C. The yeast prepared asabove possesses characteristics by which it is readily distinguishable;it is more fiocculent than ordinary yeast, and possesses a higherspecific gravity; it is furthermore distinguishable by the associationwith it of the salt or salts added to the wort. It is very readilydistinguished by its effect upon brewers Wort when used to ferment thesame, the fermentation being better and quicker and resulting in a beerof better foamkeeping quality, improved flavor and greater stability. Itis, above all, distinguished by its quick settling and superiorclarification qualities, so that the resulting beer can be put on themarket within a shorter period. By reason-of its peculiar flakycharacter it envelope the albumin'oids and hop resins suspended in thebeer and acts as clarifying agent, as a result of which beers producedby means of this yeast are readily finished without the use of chips,thereby resulting in a great economy of time and labor. This readyclarification is probably closely associated with the highly flocculentcharacter of the yeast.

It is necessary that the brewers worts to be fermented by means of theprepared yeast should receive an addition comprising the same salts usedfor the cultivation of the yeast. In the instance given there ispreferably added per liter of the wort; 0.6 gr. calcium sulfate, 0.15gr. calcium chlorid, 0.03 gr. magnesium sulfate, 0.03 gr. magnesiumchlorid, 0.06 gr. potassium chlorid. Good results are obtained bycultivating the yeast in successive worts containing only a portion ofthe above mentioned salts, as, for instance, calcium sulfate andmagnesium sulfate, or calcium sulfate and calcium chlorid, or calciumsulfate and magnesium chlorid; the best results, however, are obtainedby proceeding as above described.

I claim:--

1. The process of preparing yeast which consists in propagating theyeast in successive worts containing regularly increasing proportions ofan alkali earth metal'sulfate, substantially as described. 2. Theprocess of preparing yeast which consists in propagating the yeast insuccessive worts containing regularly increasing proportions of sulfatesof different alkali earth metuisfisubstantlaily as'described.

3. The process of preparing yea st which consists in propagating theyeast in successive worts containing regularly increasing proportions ofalkali earth metal sulfates and chlorids, substantially as described.

4. The process of preparing yeast which consists in propagating theyeast in successive worts containing regularly increasing proportions ofalkali earth metal sulfates and chlorids, and potassium chlorid,substantially as described.

5. The process of preparing yeast which consists in propagating theyeast through several generations in each of several successive wortscontaining regularly increasing proportions of an alkali earth metalsulfate, substantially as described.

6. The process of preparing yeast which consists in propagating theyeast through several generations in each T of several successive worts'containing regularly increasing proportions of alkali earth metalsulfates and ehlorids, substantially as described.

7. The process of fermenting wort which consists in inoculating the samewith yeast produced by propagation in successive worts containingregularly increasing pro portions of an alkali earth metal sulfate,substantially as described.

S. The process of fermenting wort which consists in inoculating the samewith yeast produced by propagation in sulfates and chlorids, andinoculating it with yeast pro-' duced by propagation in successive 'ortscontaining regularly increasing proportions of the same salts,substantially as described. 4

11. A prepared yeast distinguished by its llocculent character, by itsrapid and complete clarification or settling in beer in the absence ofchips, and by its relatively high proportion of associated mineral saltsof alkali earth metals, substantially as described. I

In testimony whereof, I aflix my signature in presence of two witnesses.

MAX WALLERSTEIN.

Witnesses:

. FREDERICK BATH, Cms. L. Honnnm.

